1. Field of the Invention
This invention relates to a method and apparatus for cooling a metal extrusion, such as an aluminum extrusion and, more specifically, it relates to such a system wherein precise control of the spray pattern and amount of cooling liquid delivered is provided.
2. Description of the Prior Art.
It has long been known to cool a metal workpiece by quenching, as by the use of air or water. See, generally, U.S. Pat. Nos. 3,996,075, 4,106,956 and Canadian Patents 1,058,109 and 1,206,354.
It has also been known to deliver cooling air or water by means of a spray or to quench such a metal workpiece by immersion of the workpiece in cooling water. See U.S. Pat. Nos. 3,850,763 and 3,874,213.
The use of a fixed array ring of water spray nozzles which direct water onto the periphery of a steel pipe having an elevated temperature is disclosed in The Making, Shaping and Heat Treating of Steel, page 1043, 10th Ed., 1985.
Despite the foregoing known systems, there remains a very real and substantial need for a quenching system for use with extrusions which will be adapted to provide highly efficient quenching even when products have irregular configurations and varying wall thicknesses.